diff options
| -rw-r--r-- | include/uapi/linux/pidfd.h | 12 | ||||
| -rw-r--r-- | kernel/exit.c | 15 | ||||
| -rw-r--r-- | kernel/pid.c | 12 | ||||
| -rw-r--r-- | tools/testing/selftests/pidfd/pidfd.h | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/pidfd/pidfd_wait.c | 304 |
5 files changed, 164 insertions, 183 deletions
diff --git a/include/uapi/linux/pidfd.h b/include/uapi/linux/pidfd.h new file mode 100644 index 000000000000..5406fbc13074 --- /dev/null +++ b/include/uapi/linux/pidfd.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ + +#ifndef _UAPI_LINUX_PIDFD_H +#define _UAPI_LINUX_PIDFD_H + +#include <linux/types.h> +#include <linux/fcntl.h> + +/* Flags for pidfd_open(). */ +#define PIDFD_NONBLOCK O_NONBLOCK + +#endif /* _UAPI_LINUX_PIDFD_H */ diff --git a/kernel/exit.c b/kernel/exit.c index 733e80f334e7..1f51c27bae59 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1474,7 +1474,7 @@ end: return retval; } -static struct pid *pidfd_get_pid(unsigned int fd) +static struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags) { struct fd f; struct pid *pid; @@ -1484,8 +1484,10 @@ static struct pid *pidfd_get_pid(unsigned int fd) return ERR_PTR(-EBADF); pid = pidfd_pid(f.file); - if (!IS_ERR(pid)) + if (!IS_ERR(pid)) { get_pid(pid); + *flags = f.file->f_flags; + } fdput(f); return pid; @@ -1498,6 +1500,7 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop, struct pid *pid = NULL; enum pid_type type; long ret; + unsigned int f_flags = 0; if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED| __WNOTHREAD|__WCLONE|__WALL)) @@ -1531,9 +1534,10 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop, if (upid < 0) return -EINVAL; - pid = pidfd_get_pid(upid); + pid = pidfd_get_pid(upid, &f_flags); if (IS_ERR(pid)) return PTR_ERR(pid); + break; default: return -EINVAL; @@ -1544,7 +1548,12 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop, wo.wo_flags = options; wo.wo_info = infop; wo.wo_rusage = ru; + if (f_flags & O_NONBLOCK) + wo.wo_flags |= WNOHANG; + ret = do_wait(&wo); + if (!ret && !(options & WNOHANG) && (f_flags & O_NONBLOCK)) + ret = -EAGAIN; put_pid(pid); return ret; diff --git a/kernel/pid.c b/kernel/pid.c index b2562a7ce525..74ddbff1a6ba 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -43,6 +43,7 @@ #include <linux/sched/task.h> #include <linux/idr.h> #include <net/sock.h> +#include <uapi/linux/pidfd.h> struct pid init_struct_pid = { .count = REFCOUNT_INIT(1), @@ -522,7 +523,8 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) /** * pidfd_create() - Create a new pid file descriptor. * - * @pid: struct pid that the pidfd will reference + * @pid: struct pid that the pidfd will reference + * @flags: flags to pass * * This creates a new pid file descriptor with the O_CLOEXEC flag set. * @@ -532,12 +534,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) * Return: On success, a cloexec pidfd is returned. * On error, a negative errno number will be returned. */ -static int pidfd_create(struct pid *pid) +static int pidfd_create(struct pid *pid, unsigned int flags) { int fd; fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid), - O_RDWR | O_CLOEXEC); + flags | O_RDWR | O_CLOEXEC); if (fd < 0) put_pid(pid); @@ -565,7 +567,7 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags) int fd; struct pid *p; - if (flags) + if (flags & ~PIDFD_NONBLOCK) return -EINVAL; if (pid <= 0) @@ -576,7 +578,7 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags) return -ESRCH; if (pid_has_task(p, PIDTYPE_TGID)) - fd = pidfd_create(p); + fd = pidfd_create(p, flags); else fd = -EINVAL; diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index a2c80914e3dc..01f8d3c0cf2c 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -46,6 +46,10 @@ #define __NR_pidfd_getfd -1 #endif +#ifndef PIDFD_NONBLOCK +#define PIDFD_NONBLOCK O_NONBLOCK +#endif + /* * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c * That means, when it wraps around any pid < 300 will be skipped. diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c index 7079f8eef792..be2943f072f6 100644 --- a/tools/testing/selftests/pidfd/pidfd_wait.c +++ b/tools/testing/selftests/pidfd/pidfd_wait.c @@ -17,10 +17,15 @@ #include <unistd.h> #include "pidfd.h" -#include "../kselftest.h" +#include "../kselftest_harness.h" #define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr))) +/* Attempt to de-conflict with the selftests tree. */ +#ifndef SKIP +#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) +#endif + static pid_t sys_clone3(struct clone_args *args) { return syscall(__NR_clone3, args, sizeof(struct clone_args)); @@ -32,9 +37,8 @@ static int sys_waitid(int which, pid_t pid, siginfo_t *info, int options, return syscall(__NR_waitid, which, pid, info, options, ru); } -static int test_pidfd_wait_simple(void) +TEST(wait_simple) { - const char *test_name = "pidfd wait simple"; int pidfd = -1, status = 0; pid_t parent_tid = -1; struct clone_args args = { @@ -50,76 +54,40 @@ static int test_pidfd_wait_simple(void) }; pidfd = open("/proc/self", O_DIRECTORY | O_RDONLY | O_CLOEXEC); - if (pidfd < 0) - ksft_exit_fail_msg("%s test: failed to open /proc/self %s\n", - test_name, strerror(errno)); + ASSERT_GE(pidfd, 0); pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); - if (pid == 0) - ksft_exit_fail_msg( - "%s test: succeeded to wait on invalid pidfd %s\n", - test_name, strerror(errno)); - close(pidfd); + ASSERT_NE(pid, 0); + EXPECT_EQ(close(pidfd), 0); pidfd = -1; pidfd = open("/dev/null", O_RDONLY | O_CLOEXEC); - if (pidfd == 0) - ksft_exit_fail_msg("%s test: failed to open /dev/null %s\n", - test_name, strerror(errno)); + ASSERT_GE(pidfd, 0); pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); - if (pid == 0) - ksft_exit_fail_msg( - "%s test: succeeded to wait on invalid pidfd %s\n", - test_name, strerror(errno)); - close(pidfd); + ASSERT_NE(pid, 0); + EXPECT_EQ(close(pidfd), 0); pidfd = -1; pid = sys_clone3(&args); - if (pid < 0) - ksft_exit_fail_msg("%s test: failed to create new process %s\n", - test_name, strerror(errno)); + ASSERT_GE(pid, 0); if (pid == 0) exit(EXIT_SUCCESS); pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); - if (pid < 0) - ksft_exit_fail_msg( - "%s test: failed to wait on process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - - if (!WIFEXITED(info.si_status) || WEXITSTATUS(info.si_status)) - ksft_exit_fail_msg( - "%s test: unexpected status received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - close(pidfd); - - if (info.si_signo != SIGCHLD) - ksft_exit_fail_msg( - "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_signo, parent_tid, pidfd, - strerror(errno)); - - if (info.si_code != CLD_EXITED) - ksft_exit_fail_msg( - "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_code, parent_tid, pidfd, - strerror(errno)); - - if (info.si_pid != parent_tid) - ksft_exit_fail_msg( - "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_pid, parent_tid, pidfd, - strerror(errno)); - - ksft_test_result_pass("%s test: Passed\n", test_name); - return 0; + ASSERT_GE(pid, 0); + ASSERT_EQ(WIFEXITED(info.si_status), true); + ASSERT_EQ(WEXITSTATUS(info.si_status), 0); + EXPECT_EQ(close(pidfd), 0); + + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_EXITED); + ASSERT_EQ(info.si_pid, parent_tid); } -static int test_pidfd_wait_states(void) +TEST(wait_states) { - const char *test_name = "pidfd wait states"; int pidfd = -1, status = 0; pid_t parent_tid = -1; struct clone_args args = { @@ -135,9 +103,7 @@ static int test_pidfd_wait_states(void) }; pid = sys_clone3(&args); - if (pid < 0) - ksft_exit_fail_msg("%s test: failed to create new process %s\n", - test_name, strerror(errno)); + ASSERT_GE(pid, 0); if (pid == 0) { kill(getpid(), SIGSTOP); @@ -145,127 +111,115 @@ static int test_pidfd_wait_states(void) exit(EXIT_SUCCESS); } - ret = sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL); - if (ret < 0) - ksft_exit_fail_msg( - "%s test: failed to wait on WSTOPPED process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - - if (info.si_signo != SIGCHLD) - ksft_exit_fail_msg( - "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_signo, parent_tid, pidfd, - strerror(errno)); - - if (info.si_code != CLD_STOPPED) - ksft_exit_fail_msg( - "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_code, parent_tid, pidfd, - strerror(errno)); - - if (info.si_pid != parent_tid) - ksft_exit_fail_msg( - "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_pid, parent_tid, pidfd, - strerror(errno)); - - ret = sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0); - if (ret < 0) - ksft_exit_fail_msg( - "%s test: failed to send signal to process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - - ret = sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL); - if (ret < 0) - ksft_exit_fail_msg( - "%s test: failed to wait WCONTINUED on process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - - if (info.si_signo != SIGCHLD) - ksft_exit_fail_msg( - "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_signo, parent_tid, pidfd, - strerror(errno)); - - if (info.si_code != CLD_CONTINUED) - ksft_exit_fail_msg( - "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_code, parent_tid, pidfd, - strerror(errno)); - - if (info.si_pid != parent_tid) - ksft_exit_fail_msg( - "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_pid, parent_tid, pidfd, - strerror(errno)); - - ret = sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, NULL); - if (ret < 0) - ksft_exit_fail_msg( - "%s test: failed to wait on WUNTRACED process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - - if (info.si_signo != SIGCHLD) - ksft_exit_fail_msg( - "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_signo, parent_tid, pidfd, - strerror(errno)); - - if (info.si_code != CLD_STOPPED) - ksft_exit_fail_msg( - "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_code, parent_tid, pidfd, - strerror(errno)); - - if (info.si_pid != parent_tid) - ksft_exit_fail_msg( - "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_pid, parent_tid, pidfd, - strerror(errno)); - - ret = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0); - if (ret < 0) - ksft_exit_fail_msg( - "%s test: failed to send SIGKILL to process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_STOPPED); + ASSERT_EQ(info.si_pid, parent_tid); - ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); - if (ret < 0) - ksft_exit_fail_msg( - "%s test: failed to wait on WEXITED process with pid %d and pidfd %d: %s\n", - test_name, parent_tid, pidfd, strerror(errno)); - - if (info.si_signo != SIGCHLD) - ksft_exit_fail_msg( - "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_signo, parent_tid, pidfd, - strerror(errno)); - - if (info.si_code != CLD_KILLED) - ksft_exit_fail_msg( - "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_code, parent_tid, pidfd, - strerror(errno)); - - if (info.si_pid != parent_tid) - ksft_exit_fail_msg( - "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", - test_name, info.si_pid, parent_tid, pidfd, - strerror(errno)); - - close(pidfd); - - ksft_test_result_pass("%s test: Passed\n", test_name); - return 0; + ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_CONTINUED); + ASSERT_EQ(info.si_pid, parent_tid); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_STOPPED); + ASSERT_EQ(info.si_pid, parent_tid); + + ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0), 0); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_KILLED); + ASSERT_EQ(info.si_pid, parent_tid); + + EXPECT_EQ(close(pidfd), 0); } -int main(int argc, char **argv) +TEST(wait_nonblock) { - ksft_print_header(); - ksft_set_plan(2); + int pidfd, status = 0; + unsigned int flags = 0; + pid_t parent_tid = -1; + struct clone_args args = { + .parent_tid = ptr_to_u64(&parent_tid), + .flags = CLONE_PARENT_SETTID, + .exit_signal = SIGCHLD, + }; + int ret; + pid_t pid; + siginfo_t info = { + .si_signo = 0, + }; + + /* + * Callers need to see ECHILD with non-blocking pidfds when no child + * processes exists. + */ + pidfd = sys_pidfd_open(getpid(), PIDFD_NONBLOCK); + EXPECT_GE(pidfd, 0) { + /* pidfd_open() doesn't support PIDFD_NONBLOCK. */ + ASSERT_EQ(errno, EINVAL); + SKIP(return, "Skipping PIDFD_NONBLOCK test"); + } + + ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + ASSERT_LT(ret, 0); + ASSERT_EQ(errno, ECHILD); + EXPECT_EQ(close(pidfd), 0); + + pid = sys_clone3(&args); + ASSERT_GE(pid, 0); + + if (pid == 0) { + kill(getpid(), SIGSTOP); + exit(EXIT_SUCCESS); + } - test_pidfd_wait_simple(); - test_pidfd_wait_states(); + pidfd = sys_pidfd_open(pid, PIDFD_NONBLOCK); + EXPECT_GE(pidfd, 0) { + /* pidfd_open() doesn't support PIDFD_NONBLOCK. */ + ASSERT_EQ(errno, EINVAL); + SKIP(return, "Skipping PIDFD_NONBLOCK test"); + } + + flags = fcntl(pidfd, F_GETFL, 0); + ASSERT_GT(flags, 0); + ASSERT_GT((flags & O_NONBLOCK), 0); + + /* + * Callers need to see EAGAIN/EWOULDBLOCK with non-blocking pidfd when + * child processes exist but none have exited. + */ + ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + ASSERT_LT(ret, 0); + ASSERT_EQ(errno, EAGAIN); + + /* + * Callers need to continue seeing 0 with non-blocking pidfd and + * WNOHANG raised explicitly when child processes exist but none have + * exited. + */ + ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED | WNOHANG, NULL); + ASSERT_EQ(ret, 0); - return ksft_exit_pass(); + ASSERT_EQ(fcntl(pidfd, F_SETFL, (flags & ~O_NONBLOCK)), 0); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_STOPPED); + ASSERT_EQ(info.si_pid, parent_tid); + + ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_EXITED); + ASSERT_EQ(info.si_pid, parent_tid); + + EXPECT_EQ(close(pidfd), 0); } + +TEST_HARNESS_MAIN |